From “Chapter IV: Of the Third Article”:
Question
IV
Not all matters touching the Conception of
Christ are supernatural, but most of them are
In this mystery we perceive that
some things were done, which transcend the order of nature, some by the power
of nature. Thus, in believing that the body of Christ was formed from the most
pure blood of the Virgin Mother, we therein acknowledge human nature, seeing
that this is a law common to all human bodies. But what transcends the order of
nature and human understanding is, that, as soon as the Blessed Virgin,
assenting to the words of the angel, said: Behold
the handmaid of the Lord, be it unto me according to thy word, the most
sacred body of Christ was immediately formed, and to it was united a soul
actually enjoying the use of reason; and thus, in the same instant of time, he
was perfect God and perfect man. That this was the new and admirable work of
the Holy Ghost, no one can doubt, whereas, according to the order of nature,
no body, unless within the prescribed period of time, can be endued with a
human soul. (The Catechism of the Council of Trent [trans.
Theodore Alois Buckley [London: George Routledge and Co., 1852], 42, emphasis
in bold added)
